2013 marks the centennial of a decision that allowed the destruction of one of America’s wilderness treasures: Hetch Hetchy Valley in Yosemite National Park.

On Dec. 19, 1913, President Woodrow Wilson signed the ill-conceived Raker Act, which turned the spectacular, glacier-carved valley into a mere “water tank,” in the words of naturalist John Muir.

As former superintendents of Yosemite, we call on Congress to amend this legislation to better reflect the best interests of the American people, drain Hetch Hetchy Reservoir and heal the greatest blemish in all our national parks.

A century ago, 200 newspaper editors nationwide saw the Raker Act as a raid on the very purpose of national parks to protect wild and wonderful natural scenery for every American. But San Francisco, the intended beneficiary, was recovering from a terrible earthquake, and officials eager to restore the city saw Yosemite as an ideal place to collect an abundant, free supply of water.

Sympathy in the U. S. Congress was on their side, and the result was a 430-foot-high concrete dam that drowned Hetch Hetchy Valley under 300 feet of water.

The public outcry prompted Congress to establish the National Park Service, to ensure that our national parks would be managed as a national system, not for local benefit.

Subsequent proposals to build dams in Yellowstone and the Grand Canyon were defeated. In the 100 years since passage of the Raker Act, no other significant development has been allowed in any of our national parks.

Writer and historian Wallace Stegner called national parks “the best idea we ever had,” and we heartily agree. They preserve our most glorious natural heritage for the benefit of all. The centennial of the Raker Act prompts us to ask whether we can do a better job of upholding those principles.

Yosemite National Park was named a UNESCO World Heritage Site in 1984 for its exceptional natural beauty, unique landform features and distinctive reflections of geologic history. Hetch Hetchy Valley once possessed all of these characteristics but today attracts few visitors to the reservoir’s shore.

Meanwhile its twin, Yosemite Valley, 15 miles to the south, is so congested that the National Park Service is working on a plan to reduce tourist activity there.

What better time for Americans to ask their elected representatives to reconsider the Raker Act?

Careful studies including reports by the University of California, Davis, the Environmental Defense Fund and the California Department of Water Resources have confirmed that San Francisco’s water and power needs could be met without Hetch Hetchy Reservoir.

San Francisco could expand its surface and groundwater storage outside Yosemite and filter, recycle and conserve water. Other California cities have successfully taken such steps, and in far greater magnitude.

It’s time for Congress to take bi-partisan action on behalf of all the American people by returning Hetch Hetchy Valley to Yosemite National Park. The Raker Act amendment should ensure that the city retains its hydroelectric facilities, pipelines and other reservoirs in the Tuolumne River watershed, and of course should provide adequate time to plan and implement changes to its water system.

A century ago, our nation sought to tame the wilderness with large-scale engineering projects, occasionally with destructive results. Today we should commit to undoing one of the worst examples of that destruction. And tomorrow, we can watch a magnificent valley emerge from the depths.

Let’s make Yosemite National Park whole once again.

Robert Binnewies, B.J. Griffin and David Mihalic are former superintendents of Yosemite National Park. They wrote this for this newspaper.